Stabilization of fatty materials



Patented Ar, 24, 1945 s'rmrzs'rrow or FATTY MAT Guy W. Phelps and HowardC. Black, Chicago, Ill.,

assignors' to Industrial Patents Corporatio Chicago, 111-,

a corporation of Delaware No Drawing. Application December 12,1941,Serial No. 422,677

Claims.

This invention is directed to the preparation of stable fatty materialsand more particularly it relates to the simple treatment of fattymaterials under conditions that the prdouct has greater stability andreversion resistance on aging as well as improved color and organolepticproperties.

The treatment of fatty materials with antioxidents in order to improvetheir stability has been known for years. Numerous materials have beensuggested for this purpose, some of which have been quite successful.However, there is a great room for improvement in the stabilization offatty materials, particularly in the case of edible products. In theprocessing of fatty materials it has been the general practice toincorporate the antioxidant agent near the end of the treatment becauseit was believed that some of the agent could be removed or destroyedduring this processing and little couldbe gained by the incorporation ofthe agent earlier in the process.

It has now been found, however, that the incorporation of a certain fewclasses of antioxidants prior to or during the deodorization process inthe treatment of fatty materials produces a final product havingexceptional reversion resistance and stability. This is a surprising andunpredictable result since there is no apparent alteration in the fattymaterial during the deodorization due to the presence of these specificagents, yet the product has entirely different aging characteristicsthan one in which these same agents are added directly after thedeodorization. Strangely enough this property does not exist to thisstartling extent with other effective antioxidants ordinarily employedwith fatty materials, such as carotenoid pigments, lecithin, or naturalantioxidants found in sesame oil, soy bean call, or palm oil. The twoclasses of material which have been found to exhibit this unusuallyeffective result fall into the following organic classes: (1) polyhydrlcphenols and their partial esters, particularly gum guaiac, and (2)oleflnic, and/or hydroxy substituted, low molecular weightpolycarboxylic acids and their anhydrides and their esters, particularlycitric acid.

It has also been discovered that during the deodorization of the fattymaterial in the presence of one or more of these agents the step ofheating the steam vapors leaving the body of fatty material so thatthere is no tendency to reflux,- not only substantially shortens theperiod of treatment and permits lower liquid temperatures withconsequent minimization of hydrolysis, but also brings about the removalof many impurities not previously separated and causes less breakdown ofthe product under treatment. The products are of even better color,odor, taste, and have greater resistance to reverting and degrading.Furthermore, and of utmost importance, crude materials, many of whichhave previously not been considered useful, can be employed in thepreparation of first grade products without expensive regfining steps.In fact, many of such substances have now been found to yield productsof greater stability because of the omission of the usual refining step.

In general the treatment of the fatty material in the preparation ofedible products involves the following steps: Refining by treatment withalkali followed by centrifugation or by solvent extraction in order toremove fatty acids, gums,

and related materials; bleaching and filtering with fuilers earth,hydrogenating the fatty material, if necessary, in the presence of anickel catalyst; filtering-with or without filter aids, such askieselguhr, fullers earth or filtercel; deodorization in the followingmanner.

The deodorizing treatment of the fatty material is generally carried outaccording to the invention by placing liquid or liquefied crude and/orrefined fatty material along with about 0.001% to 1% of the antioxidant,such as gum guaiac, citric acid, or mixtures thereof, into a heated,closed vessel having open steam ports in the bottom thereof. Thematerial at a temperature of about 200 to 450 F., depending on thenature of the composition under treatment is usually subjected to avacuum, generally about twenty to thirty inches of mercury, e. g. 29inches, whilie passing steam therethrough at a temperature slightlyabove that of the material under treatment.

Heat is preferably applied in the upper part 'of the vessel eitherdirectly by steam or preferably by indirect means so that the vaporswhich are withdrawn near the top are prevented from cooling materiallyand are preferably raised in temperature thereby preventing substantialcondensation and reflux of vaporized impurities. The temperature in theupper part of the vessel is advantageously maintained at the temperatureof or nearthe temperature of the liquid, preferably at a temperature ofat least about 250 F.

, This may be obtained by passing steam, mineral oil vapor, diphenylvapor, diphenyl ether vapor, or other suitable vapors or mixed vapors,heat exchange liquids including molten salts or the like, throughpassages, pipes, tubes, zones, or other indirect heating means in thevapor path, in the walls and/or the outside of the deodorizing vessel.

and then The vapors are withdrawn near the top of th vessel and passedthrough a condenser to recover high boiling organic materials, then to asteam ejector and finally a barometric condenser wherein the steam iscondensed.

The stability and reversion resistance of the Furthermore, the productsobtained from this procedre have a substantially lower impurity content,particularly of a fatty acid nature, and the smoke point thereof israised considerably. These improved results are obtained with treatingfor only a traction of the time normally employed.

Absolute values cannot be odorization treatment of all fatty materialsbecause of the variable nature of the valuablshconereorperation in thedeodorization of vegetable oils of various types, it is desirable toemploy oil temperatures of the order of 350 to 450 F. Steam is usuallyintroduced in such a heated mixture at a pressure of about 50 to 150pounds per square inch and a temperature of about 300 to 400 F. In suchoperation the temperature of the vapors is preferably kept at a value of250 to 350 F. or higher in order to avoid condensation, whereas in priorpractice, temperatures below 200 F. to 250 F. were normally existent.

n the other hand, with animal fats it has now been found that althoughtheabove operating temperatures are effective, even more desirableresults are obtained by employing oil temperature of 200 to 300 1'2,preferably at least 250 F., with slightly lower vapor and temperaturesthan those employed in the vegetable oil treatment.

, The following examples are given for the purpose of illustrating thepresent invention but are not intended to be limiting on the scopethereof.

A series of animal fats, oleo oil, lard and edible tallow, obtained byrendering were alkali refined. filtered and then deodorized with steamat a temperature between 350 and 450 F. and a vacuum of abouttwenty-nine inches of mercury.

Some of the samples were deodorized without an antioxidant and theantioxidant added subsequent to the deodorization treatment. In othersthe antioxidant was added prior to deodorization and was present in allsubsequent tests. The following table indicates the results obtainedfrom these tests:

' Active in hours Material Oleo oil Do 0.002 citric acid...

It is apparent from the foregoing results that the addition ofantioxidant inhibitors to the fat prior to deodorization greatlyinhibits reversion. Such results could not be termed predictable in viewof the present state of the art.

As pointed out hereinbefore the employment product is surprisinglyincreasedsteanr saunas j fixed for the deof lower temperatures for thedeodorisation of animal fats likewise brings about improved results inreversion resistance. The combination of this lower temperaturetreatment with antioxidants produces even' greater stability andreversion resistance. The following table settin: forth results obtainedon treating lard under various conditions bears this out:

Material timed timcat m 1! time inhourl 140 r.

Larddeodorised6850F 0 21m su misstateme- .2 tee--- a d i o o% gusise as22d 22d al 118 8 odor ised at 200%F 9- ya The combination of. the lowtemperature deodorization with'the use of gum guaiac inhibitor prior tosaid deodorizatlon enables one to produce an animal fat which isodorless. tasteless,

' suits which are much and very resistant not only to rancidity but toreversion as well. Each step is of itself valuable, but the combinationof the two yields rebetter than either alone.

The following table illustrates the unusual emcacy of gum guaiac andcitric acid as compared with natural antioxidants present in crude soybean oil or palm oil. In each case the lard was deodorized at 400 F. forfive hours.

Active oxygen stability in hours Material treated reversion at It can beseen that the gum guaiac and citric acid diflfer my. eflect on the lardwhen added prior lar use of crude soy bean oil and crude The followingtable gives odorization of prime steam gum guaiac added in acetic acidsolution:

It is seen that the fatty acid content is reduced much further when thejacket is on The values for the same type of raw material as in theforegoing table, except that the original free fatty acid content ishigher. are given in this table.

Jacket on 250lba/sq. in 25 min lar o. Free fatty acids alterdeodorizing... 0.05 0.14. Flavoroi deodorizedproductnsu... Very goodGood.

Again it is seen that the free fatty acids are Days before agents mayalso be more emciently removed when the vapor temperatures are higher.

Although the above examples are directed to the treatment of animalfats, similar results are obtained with vegetable oils and fats by theincorporation of one of the two type antioxidants prior to thedeodorization treatment. Among the materials which may be improved bythe present means are olive oil, butter, lard, cottonseed oil, soy beanoil, peanut oil, tallow, sesame oil, coconut oil, palm oil, palm kerneloil, saffiower oil, sun flower oil, linseed oil, teaseed oil,chaulmoogra oil, menhadden oil, sardine oil, spermaceti, sperm oil,whale oil, fish liver oils, vitamin concentrates, beeswax, wool fat,castor oil, almond oil, cocoa butter, cashew nut oil, cashew nut shelloil, chicken fat, kapol: oil, corn oil, rape oil, oiticica oil, perillaoil, tung oil, the full and partial hydrogenated derivatives of theseoils, the individual fatty glyceride acids therein and mixtures thereof.

Among the suitable modifying agents which may be employed during thedeodorization are the following fumaric acid, aconitic acid, citramalicacid, itamalic acid, citraconic acid, paraconic acid, itaconic acid,protaconic acid, isaconic acid, mesaconic acid, mucic acid, tartaricacid, tartronic acid, hydroxyglutaric, trihydroxyglutaric, and otherhydroxy and/or unsaturated polycarboxylic acids or their esters oranhydrides; resorcinol,

v pyrogallol, pyrocatechol, hydroquinone, phloroglucinol, gumguaiac,hexy1resorcinol, dihydroxynaphthalene, their low molecular weightfatty acid acyl derivatives or their low molecular weight fatty acidpartial ester derivatives and tures of any of the foregoing materials.

Antioxidants, solvents, and-other modifying incorporated in the fattyacid composition under terials are g cerol, polyglycerols, ethyleneglycol,-polyglycols, propylene glycols, tetrahydrofurfuryl alcohol,ethyl alcohol, acetic acid, salicylic acid, benzoic acid,pyrogallol-acetone condensation product, aminophenols,hydroxynaphthalenes, fatty acid partial glycerides, fatty acidalkylolamides. amino-esters of fatty acids, and ultimate compositionObviously, many modifications and variations citric acid, malic acid,maleic acid;

of the invention hereinbefore set forth maybe made withoutdistinguishing from the spirit and scope thereof, and therefore onlysuch limitations should be imposed as are indicated in the appendedclaims.

We claim:

1. The process which comprises steam deodorizing a relativelynon-volatile fatty material in the presence of a small amount of gumguaiac.

2. The process which comprises steam deodorin the presence of about0.001% to 1% of gum llaiac.

8. The process which comprises steam deodorizing a fatty acid ester of apolyhydric alcohol under vacuum and in the presence of about 0.001% to1% of gum uaiac.

4. The process which comprises deodorlzing a fatty acid ester of lowvolatility with steam while under a vacuum of at least 2*! inches ofmercury and at a temperature of at least 200 F'., and in the presence ofa small amount of gum guaiac.

5. The process which comprises deodorizing a,

fatty acid ester of 10W volatility with steam while under a vacuum of atleast 27 inches of mercury and at a temperature of at least 200 F.. andin the presence of about 0.001% to 1% of gum guaiac.

6. The process which comprises deodorizing a fatty acid ester of lowvolatility with steam while under avacuum and in the presence of 0.001to 1% of gum guaiac.

7. The process of retarding flavor reversion in animal fatty materialwhich comprises deodorizing the same in the presence of gum guaiac.

treatment. Among these ma- 8. The process of retarding flavor reversionin fatty material which comprises deodorizing the same in the presenceof gum guaiac.

9. The process of retarding flavor reversion in fatty material whichcomprises subjecting said fatty. material to a temperature of from about200 F. to 450 F. under vacuum in the presence of gum guaiac and for asufllcient period to effeet the substantial deodorization thereof.

10. The process of retarding flavor reversion in fatty material whichcomprises steam deodorizing the same under vacuum in the presence of gumguaiac.

GUY W. PHELPS. HOWARD 0. BLACK.

a relatively non-volatile fatty material in

